Manufacture of printed circuit boards may result in defects such as defective attachments where the integrated circuit chips do not have a strong bond to the circuit board. Often, a customer will order printed circuit boards to install them in a larger system, such as computers, printers, TVs, etc. If the boards have defects, the customer either has to send the boards back or rework them before installing them in the larger system.
Another possibility results in the printed circuit boards being installed in the larger system and the larger system being shipped to an end customer. The defect may allow the board to operate for a period of time before failing. The end customer may have to call for field support. Currently, to repair the defect the field service technician will have to take the system back from the end user and send it out for repairs, or replace the entire circuit board on site.
These options cost much more than desired. Not only is the repair more expensive in either case, the equipment to make the repairs costs a lot of money as well. The ability to make the repairs at the end user's site or at the system manufacturer's site would keep the costs down and allow for more reliable systems.